content: /*
   * Copyright 2011-2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package ix;
  
  import java.util.Iterator;
  
  final class IxTakeLast<T> extends IxSource<T, T> {
  
      final int n;
  
      IxTakeLast(Iterable<T> source, int n) {
          super(source);
          this.n = n;
      }
  
      @Override
      public Iterator<T> iterator() {
          return new TakeLastIterator<T>(source.iterator(), n);
      }
  
      static final class TakeLastIterator<T> extends IxSourceQueuedIterator<T, T, T> {
  
          int n;
  
          TakeLastIterator(Iterator<T> it, int n) {
              super(it);
              this.n = n;
          }
  
          @Override
          protected boolean moveNext() {
  
              int n = this.n;
              if (n != 0) {
                  Iterator<T> it = this.it;
                  while (it.hasNext()) {
                      if (n == 0) {
                          poll();
                      } else {
                          n--;
                      }
                      offer(toObject(it.next()));
                  }
                  this.n = n;
              }
  
              Object o = poll();
              if (o != null) {
                  value = fromObject(o);
                  hasValue = true;
                  return true;
              }
              done = true;
              return false;
          }
      }
  
  }
  